After working as a performance artist in New York City, Magnuson appeared opposite David Bowie in The Hunger (1983). She has also played in Making Mr. Right (1987), A Night in the Life of Jimmy Reardon (1988), Love at Large (1990), Still Breathing (1998) and The Caveman's Valentine (2001) and is familiar to TV audiences as the driven editor Catherine in the series Anything but Love (1989–92).